Strains of Lactobacillus spp. reduce chalkbrood in Apis mellifera.

Beekeeping activities have increased recently in Argentina, a country that is a major consumer of honey and other products from hives. With the advancement of monoculture areas in Argentina and worldwide, beekeepers move from one area to another in search of floral resources, thus spreading diseases such as chalkbrood, caused by the fungus Ascosphaera apis. Although there are few effective antifungals for the control of chalkbrood, different natural products have been investigated in recent years. Current research is focusing on the intestinal microbiota for the prevention of different pathogens and parasites. In this work, we analyzed the in vivo probiotic effect of three lactic acid bacteria (genus Lactobacillus spp.) isolated from pollen bread from apiaries of Jujuy province on A. apis strains from Spanish and Argentine provinces. Special hives were made for the assays, and a protective effect was observed in larvae of bees fed lactic acid bacteria added to sugar syrup at 105 CFU/mL concentrations, administered from May to September in two consecutive years. The results showed that the three lactic acid bacteria reduced larval mummification by percentages greater than 80%. Therefore, this work brings a first approximation of the in vivo probiotic effect of lactic bacteria against A. apis.

Isolation, identification, and antimycotic activity of plumbagin from Plumbago europaea L. roots, leaves and stems.

Plumbago europaea L. is a plant utilized in Palestinian ethnomedicine for the treatment of various dermatological diseases. The current investigation was designed to isolate plumbagin from P. europaea leaves, roots and for the first time from the stems. Moreover, it aimed to evaluate the antimycotic activity against three human fungal pathogens causing dermatophytosis, also against an animal fungal pathogen. The qualitative analysis of plumbagin from the leaves, stems, and roots was conducted using HPLC and spectrophotometer techniques, while the structure of plumbagin was established utilizing Proton and Carbon-13 Nuclear Magnetic Resonance (NMR) and Infrared (IR) techniques. The entire plant constituents were determined by GC-MS. Moreover, the antimycotic activity against Ascosphaera apis, Microsporum canis, Trichophyton rubrum, and Trichophyton mentagrophytes was assessed utilizing the poison food technique method. The percentage of plumbagin recorded in the leaves, stems, and roots was found to be 0.51±0.001%, 0.16±0.001%, and 1.65±0.015%, respectively. The GC-MS examination declared the presence of 59 molecules in the plant extract. The plant extract and pure plumbagin exhibited complete inhibition against all tested dermatophytes at 6.0mg/mL for the extracts and 0.2mg/mL for plumbagin. P. europaea root is the best source of plumbagin and the plant extract could represent a potential drug candidate for the treatment of dermatophytosis infections. Further studies required to design suitable dosage forms from the natural P. europaea root extracts or plumbagin alone, to be utilized for the treatment of dermatological and veterinary ailments.

Histopathology, Molecular Identification and Antifungal Susceptibility Testing of Nannizziopsis arthrosporioides from a Captive Cuban Rock Iguana (Cyclura nubila).

Chrysosporium-related fungi, the cause of superficial and deep mycoses, are an emerging infectious disease affecting not only reptiles but also immunocompromized humans. However, the information on Nannizziopsis arthrosporioides is extremely scarce. We herein characterized N. arthrosporioides isolated from a Cuban rock iguana (Cyclura nubila). Three skin ulcers were found in a Cuban rock iguana after captivity for 8 years. Microscopic examination revealed hyperplastic, hyperkeratotic, and ulcerative dermatitis coupled with numerous branched, septate fungal hyphae. The fungal culture yielded growth of zonate, felted cottony-powdery colonies with lobate margins on medium. Maximum-likelihood phylogeny tree based on the combined partial actin and partial ß-tubulin genes demonstrated that current isolates were mostly close to N. arthrosporioides. Furthermore, antifungal susceptibility test demonstrated that N. arthrosporioides had lowest minimal inhibitory concentration (MIC) values to isavuconazole, efinaconazole, and luliconazole, which may be the potential treatment of choice for N. arthrosporioides infection. The current study describes the first confirmed case of dermatomycosis caused by N. arthrosporioides of a captive reptile in Asia with detailed descriptions of the clinical, histopathological, and mycological features. The current findings provide new information on global distribution and host range of N. arthrosporioides and can raise the concern on the transboundary or emerging disease of N. arthrosporioides in Asian region.

Cyclic Synthetic Peroxides Inhibit Growth of Entomopathogenic Fungus Ascosphaera apis without Toxic Effect on Bumblebees.

In recent years, the number of pollinators in the world has significantly decreased. A possible reason for this is the toxic effects of agrochemicals reducing the immunity of insects that leads to their increased susceptibility to pathogens. Ascosphaera apis is a dangerous entomopathogenic fungus, afflicting both honeybees and bumblebees. We investigated fungicide activity of cyclic synthetic peroxides against A. apis isolated from Bombus terrestris L. The peroxides exhibited high mycelium growth inhibition of A. apis up to 94-100% at concentration 30 mg/L. EC50 values were determined for the most active peroxides. Two peroxides showed higher antifungal activity against A. apis than the commercial fungicide Triadimefon. The studied peroxides did not reduce the ability of bumblebees to fly and did not lead to the death of bumblebees. A new field of application for peroxides was disclosed.

The effect of halide salts on the production of Gymnoascus reessii polyenylpyrroles.

Addition of NaCl to the solid-phase fermentation of an Australian isolate of Gymnoascus reessii resulted in enhanced production of chloropolyenylpyrroles, while the addition of NaBr suppressed chloropolyenylpyrrole production in favor of bromo and dechloro analogues. Access to a wider selection of polyenylpyrroles provided scope for SAR comparisons on this rare class of cytotoxic natural products, with the bromo- and dechloropolyenylpyrroles displaying significantly reduced cytotoxicity. These results suggest that the chloro substituent is a critical element in the pharmacophore for this rare class of natural product.